Hi,
The problem appears in revision 201034 in version 4.9. I attached a
one-line patch that fixes it. I also reported this problem
at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57809
I bootstrapped and ran the regression tests for this patch on x86_64-linux
and all tests pass.
In method "omega_eliminate_red()" in gcc/omega.c, the loop on line 2592
should break immediately after "red_found" is set to "1". All the
iterations after "red_found" set to "1" do not perform any useful work, at
best they just set "red_found" again to "1".
There are three more similar problems in the same file gcc/omega.c:
1. omega_problem_has_red_equations(): the loop on line 4854 should break
immediately after "result" is set to "true".
2. omega_problem_has_red_equations(): the loop on line 4907 should break
immediately after "result" is set to "true".
3. omega_query_variable(): the loop on line 5252 should break immediately
after "coupled" is set to "true".
Index: gcc/omega.c
===================================================================
--- gcc/omega.c (revision 201034)
+++ gcc/omega.c (working copy)
@@ -2591,7 +2591,10 @@
for (red_found = 0, e = pb->num_geqs - 1; e >= 0; e--)
if (pb->geqs[e].color == omega_red)
- red_found = 1;
+ {
+ red_found = 1;
+ break;
+ }
if (!red_found)
{
Index: gcc/omega.c
===================================================================
--- gcc/omega.c (revision 201034)
+++ gcc/omega.c (working copy)
@@ -4853,7 +4853,10 @@
for (e = pb->num_geqs - 1; e >= 0; e--)
if (pb->geqs[e].color == omega_red)
- result = true;
+ {
+ result = true;
+ break;
+ }
if (!result)
return false;
Index: gcc/omega.c
===================================================================
--- gcc/omega.c (revision 201034)
+++ gcc/omega.c (working copy)
@@ -4906,7 +4906,10 @@
for (e = pb->num_geqs - 1; e >= 0; e--)
if (pb->geqs[e].color == omega_red)
- result = true;
+ {
+ result = true;
+ break;
+ }
if (dump_file && (dump_flags & TDF_DETAILS))
{
Index: gcc/omega.c
===================================================================
--- gcc/omega.c (revision 201034)
+++ gcc/omega.c (working copy)
@@ -5251,7 +5251,10 @@
for (e = pb->num_subs - 1; e >= 0; e--)
if (pb->subs[e].coef[i] != 0)
- coupled = true;
+ {
+ coupled = true;
+ break;
+ }
for (e = pb->num_eqs - 1; e >= 0; e--)
if (pb->eqs[e].coef[i] != 0)
-Chang
Index: gcc/omega.c
===================================================================
--- gcc/omega.c (revision 201034)
+++ gcc/omega.c (working copy)
@@ -2591,7 +2591,10 @@
for (red_found = 0, e = pb->num_geqs - 1; e >= 0; e--)
if (pb->geqs[e].color == omega_red)
- red_found = 1;
+ {
+ red_found = 1;
+ break;
+ }
if (!red_found)
{Index: gcc/omega.c
===================================================================
--- gcc/omega.c (revision 201034)
+++ gcc/omega.c (working copy)
@@ -4853,7 +4853,10 @@
for (e = pb->num_geqs - 1; e >= 0; e--)
if (pb->geqs[e].color == omega_red)
- result = true;
+ {
+ result = true;
+ break;
+ }
if (!result)
return false;Index: gcc/omega.c
===================================================================
--- gcc/omega.c (revision 201034)
+++ gcc/omega.c (working copy)
@@ -4906,7 +4906,10 @@
for (e = pb->num_geqs - 1; e >= 0; e--)
if (pb->geqs[e].color == omega_red)
- result = true;
+ {
+ result = true;
+ break;
+ }
if (dump_file && (dump_flags & TDF_DETAILS))
{Index: gcc/omega.c
===================================================================
--- gcc/omega.c (revision 201034)
+++ gcc/omega.c (working copy)
@@ -5251,7 +5251,10 @@
for (e = pb->num_subs - 1; e >= 0; e--)
if (pb->subs[e].coef[i] != 0)
- coupled = true;
+ {
+ coupled = true;
+ break;
+ }
for (e = pb->num_eqs - 1; e >= 0; e--)
if (pb->eqs[e].coef[i] != 0)
